JP2004328896A - Dc motor and fuel pump using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a DC motor which is easy to be manufactured while being a unit of a commutator and a spark quenching element, and moreover, which can be easily mounted to a shaft of an armature. <P>SOLUTION: The DC motor is constituted by using a commutator device composed of an insulation holding body 15, which is formed so as to hold a commutator piece 12 and a conductive terminal piece 14 in the arrangement state of a prescribed flat type commutator, and so as to make the commutator piece 12 capable of contacting a brush 6, a recess 17, which is formed so that adjacent conductive terminal pieces 14 are exposed to each other on the rear face side of the insulation holding body 15, and the spark quenching element 18 connected between the exposed conductive terminal pieces 14 in the recessed part 17. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a DC motor used for home electric appliances or automobile electric components, and a fuel pump configured using the DC motor.
[0002]
[Prior art]
Small DC motors used in home appliances and automotive electrical components generally have a large output, and have many excellent characteristics, such as easy control of rotation speed by using an electronic control circuit. ing. On the other hand, since the commutator rotates in a sliding state with respect to the brush, there is a problem that the brush and the commutator are mutually worn. This wear problem is largely due to the generation of sparks between the brush and the commutator. Therefore, in order to reduce the generation of sparks between the brush and the commutator, a DC motor provided with a spark quenching element such as a capacitor has been proposed (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Utility Model Registration No. 2510549 (FIGS. 1, 2 and 3)
[0004]
[Problems to be solved by the invention]
Conventionally, it is widely known that a DC motor is provided with a spark extinction element near a commutator in order to suppress a spark generated between the commutator and the brush. However, since the commutator and the spark quenching element are generally configured to be mounted on the armature shaft as separate parts, it is difficult to mount the DC commutator and the DC motor used for the in-tank type fuel pump. It was difficult to solve various problems. In addition, the difficulty in mounting causes a decrease in mass productivity.
[0005]
The present invention, in order to solve the above-mentioned problems, is a unitized commutator and spark extinction element, is easy to manufacture, and furthermore, facilitates the mounting of the armature to the shaft, It is an object to obtain a highly safe DC motor and a fuel pump using the DC motor.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a DC motor according to the present invention has a commutator device that is provided at one end of an armature, is connected to an armature winding, and is in sliding contact with a brush. The commutator device is radially centered on the axis of the armature, and is fixed to the back side of the commutator piece and the commutator piece arranged in a disc shape, and is attached to the armature winding. A conductive terminal piece to be connected, an insulating holder molded to hold the commutator piece to which the conductive terminal piece is fixed and to be able to contact the brush, and a back side of the insulating holder And a recess formed so that adjacent conductive terminal pieces are exposed to each other, and a spark extinction element connected between the conductive terminal pieces exposed in the recess.
[0007]
Further, a fuel pump according to the present invention includes a commutator device in which a commutator and a spark quenching element are unitized, and a DC motor formed by molding the outer periphery of an armature winding with a thermoplastic resin material. The motor is rotated by a motor, and the pump is configured to discharge the fuel sucked by the rotation through the inside of the DC motor.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an example of a fuel supply device for a vehicle provided with a commutator device, where M is a DC motor portion, in which a fixed magnetic pole 2 is arranged on the inner periphery of a housing 1, and an armature is provided inside. The bearing 3 is rotatably supported by a bearing 4. 3a is the axis of the armature 3. The bearing 4 is held by a bracket 5 fitted to one end of the housing 1. Reference numeral 10 denotes a planar commutator device, which is configured so that the brush 6 held by the bracket 5 comes into sliding contact with the commutator surface. The details of the commutator device 10 will be described later with reference to FIGS. P is a pump unit, which is configured to be rotated by the DC motor M to function as a pump. This fuel pump is used, for example, by being installed in a fuel tank of an automobile. The sucked fuel passes through the inside of the DC motor M and is discharged from a discharge port 5 a provided in the bracket 5. It is configured to:
[0009]
Embodiment 1 FIG.
FIGS. 2A and 2B show a commutator device 10 of the DC motor M according to Embodiment 1 of the present invention, wherein FIG. 2A is a front view, FIG. 2B is a side sectional view taken along line AA, and FIG. FIG. 3D is a sectional view taken along line BB. In the figure, the commutator pieces 12 are arranged radially and in a disk shape around a shaft hole 13 fitted in the armature shaft 3a. The commutator piece 12 is made of, for example, a carbon fired material, and is manufactured by a manufacturing method described later. On the back side of the commutator pieces 12, conductive terminal pieces 14 are fixed. The conductive terminal piece 14 is formed of a copper alloy material, and a hook-shaped terminal 14a for connecting to an armature winding (not shown) is provided at the outer peripheral end.
[0010]
The insulating holder 15 holds the commutator pieces 12 to which the conductive terminal pieces 14 are fixed radially through slits 16 having a predetermined width, and is made of a thermosetting resin material (for example, phenol resin). Material). A shaft hole 13 is formed in the center of the insulating holder 15, and a recess 17 is formed in the back surface so as to expose the conductive terminal strip 14 across the slit 16. A spark erasing element 18 formed by using a capacitor, for example, a chip capacitor, is fitted into the recess 17 and connected to the conductive terminal piece 14 straddled. This connection is made by soldering, bonding with a conductive adhesive, or fusing according to the configuration of the spark erasing element 18. The size of the recess 17 can be increased by drilling it at a position away from the shaft hole 13, so that the spark erasing element 18 can be easily fitted.
Since it is separated from the shaft hole 13, the mechanical strength of the insulating holder 15 also increases.
[0011]
It goes without saying that in the commutator device 10 of the DC motor M, the slits 16 are required between the individual commutator pieces 12 and the conductive terminal pieces 14. Therefore, the commutator piece 12 and the conductive terminal piece 14 may be individually manufactured and arranged. However, as the commutator device 10 of the present invention, the commutator piece 12 and the conductive terminal piece 14 are used as described below. It is desirable to form.
[0012]
That is, first, as shown in FIG. 4, a disc-shaped commutator piece 22 made of a carbon fired material and a conductive terminal piece 24 made of a conductive material such as a copper plate. Then, the conductive terminal piece 24 is fixed to the back surface of the disc-shaped commutator piece 22. In this case, the protrusion 22a is provided on the back surface of the commutator piece 22, the fitting hole 24a is provided on the conductive terminal piece 24 so as to correspond to the position of the protrusion 22a, and the projection 22a is fitted into the fitting hole 24a. As a result, the state is brought into a state of being joined mechanically and electrically. This connection can be made even more secure by applying tin plating to the joining surface of the commutator piece 22 and the conductive terminal piece 24 and soldering. Note that a hook-shaped terminal 14a for connecting a lead wire of an armature winding is provided at a distal end portion of the outer periphery of the conductive terminal piece 24 as described later.
[0013]
Next, as shown in FIG. 2, an insulation holder 15 made of a thermosetting resin material (for example, a phenol resin material) is molded around the commutator piece 22 and the conductive terminal piece 24. The outer peripheral portion of the conductive terminal piece 24 is molded so as to be exposed on the outer peripheral surface of the insulating holder 15 as shown in FIG. If the slits 16 are formed by cutting after molding as described above, the commutator pieces 12 and the conductive terminal pieces 14 can be easily configured. Before or after the cutting of the slit 16, the surface of the commutator piece 12 is also cut to form an accurate plane. The slit 16 is cut to the line K in FIG. 2 to divide the commutator piece 22 and the conductive terminal piece 24 to form the commutator piece 12 and the conductive terminal piece 14. The spark quenching element 18 is connected to the recess 17 via the conductive terminal piece 14 as described above.
[0014]
As described above, the unitized commutator device 10 is configured as shown in FIG. 3 by bending the hook-shaped terminal 14a as shown by the dashed line in FIG. This is fitted on the shaft 3a of the armature 3 to form a DC motor M.
[0015]
Embodiment 2 FIG.
In the DC motor M according to the first embodiment, the spark extinction element 18 is fitted into the recess 17 formed on the back surface of the insulating holder 15 of the commutator device 10, as shown in FIG. Alternatively, the spark extinction element 18 may be connected to the outer peripheral end of the conductive terminal piece 14. That is, in the drawing, the commutator piece 12, the conductive terminal piece 14, and the insulating holder 15 are configured in the same manner as in the first embodiment (shown in FIG. 2). However, the recess 17 on the back surface of the insulating holder 15 may not be provided. In this configuration, since the insulating holder 15 is formed such that the outer peripheral tip of the conductive terminal piece 14 is exposed as described above, the spark erasing element 18 is connected to the adjacent conductive tip at the outer peripheral tip of the conductive terminal piece 14. It is connected between the terminal strips 14. According to this configuration, the connection of the spark extinction element 18 is easier than that of the commutator device of the first embodiment, and the connection of the large-sized spark elimination element 18 is also possible.
[0016]
Embodiment 3 FIG.
In the first or second embodiment, the spark erasing elements 18 are individually connected. However, as shown in FIG. 7, the spark erasing elements 18 are connected in advance by connecting conductors 19 to form a necklace. If so, the spark quenching elements 18 can be connected together as shown in FIG. In this case, the connecting conductor 19 may be a thin plate or a conductive wire woven in a net shape. In this configuration, the connection is facilitated by connecting to the conductive terminal piece 14 at the connection conductor 19. 8A, at least one set of adjacent spark elimination elements is connected by a connection conductor 19, and the spark elimination element 18 is connected to the conductive terminal via the connection conductor 19, as shown in FIG. It may be connected to the piece 14. Alternatively, as shown in FIG. 8B, three sets of spark extinction elements may be connected by a connecting conductor 19. Since the lead wire of the armature winding is connected to the hook-shaped terminal 14a, if the connection conductor 19 is connected via the hook-shaped terminal 14a simultaneously with the lead wire of the armature winding, the workability of the connection is improved. Is improved.
[0017]
Embodiment 4 FIG.
As described above, the commutator device unitized with the spark quenching element 18 can be easily mounted on the armature shaft. However, the armature winding and the circumferential surface (side surface) of the commutator device are made of resin. A more excellent DC motor can be obtained by molding the material. That is, if this DC motor is used for an in-tank type fuel pump as shown in FIG. 1, the spark elimination element 18 is securely held, and the spark elimination fuel pump is obtained.
Further, it is preferable that the spark quenching element 18 is also sealed with resin for molding the armature winding and the circumferential portion of the commutator device. In this case, the fuel pump inherent in the fuel pump through which the fuel such as gasoline passes through the interior of the DC motor M drops from the commutator of the capacitor, disconnects the connection of the capacitor, disconnects the joint, and further removes the gasoline. It is possible to prevent the capacitor from deteriorating due to factors such as the above.
[0018]
【The invention's effect】
The present invention is configured as described above, and has the following effects.
[0019]
Since the commutator and the spark quenching element are configured as a unit, the mounting of the spark quenching element or the fitting of the armature to the shaft is easy, and the mass productivity is improved. Further, since the abrasion of the brush and the commutator is suppressed by the spark quenching element, a DC motor that can be used stably for a long time is obtained.
[0020]
In addition, since the spark extinction element is connected between adjacent conductive terminal pieces at the outer peripheral end of the conductive terminal piece, selection of the spark elimination element to be used is easy, and connection to the conductive terminal piece is also simplified. .
[0021]
Further, since the spark extinction element is connected in a necklace shape and is connected to the conductive terminal piece via the connecting conductor portion, mounting and connection of the spark elimination element are facilitated.
[0022]
Furthermore, when the spark quenching element is configured in a necklace shape and the connection conductor is connected to the conductive terminal piece, it is possible to simultaneously connect the lead wire of the armature winding by means such as fusing, According to this method, the connection of the lead wire of the armature winding with the spark extinction element is further facilitated.
[0023]
Since the commutator and the spark quenching element are unitized, the commutator device can be easily fitted to the armature shaft, and the outer mold applied to the armature can be applied to the commutator device. Therefore, for example, a DC motor that is safe even when applied to an in-tank type fuel pump can be obtained.
[Brief description of the drawings]
FIG. 1 is a cutaway side view of a fuel pump implementing a commutator device of the present invention.
FIG. 2 is a detailed view showing a commutator device of the present invention.
FIG. 3 is a perspective view showing a commutator device according to the first embodiment.
FIG. 4 is a component diagram for explaining a method of manufacturing the commutator device.
FIG. 5 is a perspective view showing a commutator device according to a second embodiment.
FIG. 6 is a perspective view showing a commutator device according to a third embodiment. FIG. 7 is a component diagram of a necklace-shaped spark extinction element.
FIG. 8 is a component diagram of a spark extinction element connected in a belt shape.
[Explanation of symbols]
10 commutator device, 12 commutator piece, 14 conductive terminal piece, 15 insulating holder, 16 slit, 17 recess, 18 spark extinction element.

Claims (7)

In a DC motor having a commutator device installed at one end of the armature and connected to the armature winding, and being in sliding contact with a brush, the commutator device is arranged around an axis of the armature. A radially and disk-shaped commutator piece; a conductive terminal piece fixed to the back side of the commutator piece and connected to the armature winding; An insulating holder that holds the commutator piece to which the terminal piece is fixed and is molded so that the commutator piece can contact the brush, and an adjacent conductive terminal piece on the back side of the insulating holder are exposed to each other. And a spark extinction element connected between the exposed conductive terminal pieces in the recess. In a DC motor having a commutator device installed at one end of the armature and connected to the armature winding, and being in sliding contact with a brush, the commutator device is arranged around an axis of the armature. A radially and disk-shaped commutator piece; a conductive terminal piece fixed to the back side of the commutator piece and connected to the armature winding; An insulation holder molded to hold the commutator piece to which the terminal piece is fixed and to be able to contact the commutator piece with the brush, and to expose the outer periphery of the tip of the conductive terminal piece; And a spark extinction element connected between adjacent conductive terminal pieces at an outer peripheral end of the conductive terminal piece. 3. The spark extinction element according to claim 2, wherein at least one pair of adjacent spark elimination elements is connected by a connection conductor, and the spark elimination element is connected to the conductive terminal piece via the connection conductor. DC motor. 4. The DC motor according to claim 3, wherein the spark extinction element is connected in a necklace shape by a connection conductor, and the spark elimination element is connected to the conductive terminal piece via the connection conductor. A hook-shaped terminal is provided on the conductive terminal piece of the commutator device, and a connection conductor of the spark extinction element and a lead wire of the armature winding are connected to the conductive terminal piece via the hook-shaped terminal. The DC motor according to any one of claims 2 to 4. The direct-current motor according to any one of claims 1 to 5, wherein outer circumferences of the commutator device and the armature winding are molded with a resin material. 7. A DC motor according to claim 6, wherein the DC motor is rotatably driven, and the pump is configured such that the fuel sucked by the rotary drive is discharged through the inside of the DC motor. Fuel pump.

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